Greetings all, I am currently doing some readup on the JSR 180 SIP API implementation. It clearly defines and describes all about "javax.microedition.sip" package containing interfaces and classes implementing SIP functionality. In the GCF (Generic Connection Framework) to establish connectivity with remote machine I use the foll. StreamConnection sc = (StreamConnection) Connector.open("socket://127.0.0.1:9000"); But as per the JSR 180 developers importing javax.microedition.sip will have to use the Connector.open() method but typecast it of type SipClientConnection interface as follows: SipClientConnection scc = (SipClientConnection) Connector.open("sip:firstname.lastname@example.org:5060"); When I tried this out using J2ME Wireless Toolkit 1.0.4_01 it compiled fine but I got ClassCastException during runtime which is quite logical because javax.microedition.io does not know interface SipClientConnection like it does StreamConnection. Now I am stuck here wondering what to do? Any suggesstions, advices, insights would be of great help! Thanx, adios & cheers! LearningCurve.